What is 2009 H1N1 influenza?

2009 H1N1 influenza (also called Swine Flu) is caused by a new strain of influenza virus. It has spread to many countries. Like other flu viruses, 2009 H1N1 spreads from person to person through coughing, sneezing, and sometimes through touching objects contaminated with the virus. Signs of 2009 H1N1 can include:

Some people also have diarrhea and vomiting. Most people feel better within a week. But some people get pneumonia or other serious illnesses. Some people have to be hospitalized and some die.

How is 2009 H1N1 different from regular (seasonal) flu?

Seasonal flu viruses change from year to year, but they are closely related to each other. People who have had flu infections in the past usually have some immunity to seasonal flu viruses (their bodies have built up some ability to fight off the viruses). The 2009 H1N1 flu is a new flu virus. It is very different from seasonal flu viruses. Most people have little or no immunity to 2009 H1N1 flu (their bodies are not prepared to fight off the virus).

The 2009 H1N1 influenza vaccine

Vaccines are available to protect against 2009 H1N1 influenza.

These vaccines are made just like seasonal flu vaccines.

They are expected to be as safe and effective as seasonal flu vaccines.

They will not prevent “influenza-like” illnesses caused by other viruses.

They will not prevent seasonal flu. You should also get seasonal influenza vaccine, if you want to be protected against seasonal flu.

Inactivated vaccine (vaccine that has killed virus in it) is injected into the muscle, like the annual flu shot. This page describes the inactivated vaccine. A live, intranasal vaccine (the nasal spray vaccine) is also available.

Some inactivated 2009 H1N1 vaccine contains a preservative called thimerosal to keep it free from germs. Some people have suggested that thimerosal might be related to autism. In 2004 a group of experts at the Institute of Medicine reviewed many studies looking into this theory, and found no association between thimerosal and autism. Additional studies since then reached the same conclusion.

Anyone from 25 through 64 years of age with certain chronic medical conditions or a weakened immune system

As more vaccine becomes available, these groups should also be vaccinated:

Healthy 25 through 64 year olds

Adults 65 years and older

The Federal government is providing this vaccine for receipt on a voluntary basis. However, state law or employers may require vaccination for certain persons.
WHEN
Get vaccinated as soon as the vaccine is available.
Children through 9 years of age should get two doses of vaccine, about a month apart. Older children and adults need only one dose.

Some people should not get the vaccine or should wait.

You should not get the 2009 H1N1 flu vaccine if you have a severe (life-threatening) allergy to eggs, or to any other substance in the vaccine. Tell the person giving you the vaccine if you have any severe allergies.

Also tell them if you have ever had:

a life-threatening allergic reaction after a dose of seasonal flu vaccine,

If these problems occur, they usually begin soon after the shot and last 1-2 days.

Severe problems:

Life-threatening allergic reactions to vaccines are very rare. If they do occur, it is usually within a few minutes to a few hours after the shot.

In 1976, an earlier type of swine flu vaccine was associated with cases of Guillain-Barré Syndrome (GBS). Since then, flu vaccines have not been clearly linked to GBS.

What if there is a severe reaction?

What should I look for?

Any unusual condition, such as a high fever or behavior changes. Signs of a severe allergic reaction can include difficulty breathing, hoarseness or wheezing, hives, paleness, weakness, a fast heart beat or dizziness.

What should I do?

Call a doctor, or get the person to a doctor right away.

Tell the doctor what happened, the date and time it happened, and when the vaccination was given.

Ask your provider to report the reaction by filing a Vaccine Adverse Event Reporting System (VAERS) form. Or you can file this report through the VAERS website at http://www.vaers.hhs.gov, or by calling 1-800-822-7967.

VAERS does not provide medical advice.

Vaccine injury compensation

If you or your child has a reaction to the vaccine, your ability to sue is limited by law.

However, a federal program has been created to help pay for the medical care and other specific expenses of certain persons who have a serious reaction to this vaccine. For more information about this program, call 1-888-275-4772 or visit the program's website at: http://www.hrsa.gov/countermeasurescomp/default.htm.

How can I learn more?

Ask your provider. They can give you the vaccine package insert or suggest other sources of information.